NEW Li-CONDUCTOR PROTOTYPES IN THE Li-AL-P-O CHEMICAL SPACE FOR ALL-SOLID-STATE BATTERIES

This application is based on and claims priority from U.S. Provisional Application No. 63/650,678 filed on May 22, 2024 in the U.S. Patent and Trademark Office, the disclosure of which is incorporated herein by reference in its entirety.

Materials according to embodiments relate to ionic conductors for use as solid electrolytes in Li solid-state batteries and/or for use as electrode coatings for solid-state batteries.

The fast development of portable electronics and electric vehicles has increased the demand for electrochemical energy storage system. In the meantime, the related safety issues are gathering more attention.

Due to the flammability and possible leakage, organic liquid electrolytes pose a safety risk in conventional Li-ion batteries. In this context, solid-state batteries (SSBs) are considered to be the next-generation batteries with improved safety and energy density. An all solid state battery is shown in the FIGURE. In the FIGURE, the all solid component can comprise solid cathode particles in a solid catholyte, and the solid separator can comprise a solid electrolyte.

Solid-state lithium-ion conductors with high ionic conductivities play an important role in SSBs. During the past two decades, there has been an increasing amount of work on new solid-state lithium-ion conductors (SSLICs). And most of them are focused on sulfide SSLICs with high ionic conductivities. However, very limited number of oxide materials were developed for SSBs, and so far only lithium garnet is considered to be the oxide-type electrolyte for lithium SSBs.

For solid-state electrolytes in SSBs, sulfide-based materials have high ionic conductivities (>10 mS/cm) but not really safe (H2S in air condition) and have limited electrochemical stability (for example, unstable against Li metal).

Oxide SSLICs, which own better electrochemical and chemical stability than sulfide SSLICs, have been largely limited in garnet-type materials. The ionic conductivities of reported oxide SSLICs are generally lower than those of sulfide SSLICs.

Solid state electrolyte materials with superionic conductivity and interfacial stability are desirable materials to form all-solid-state Li-metal batteries. However, several problems and challenges are currently being investigated, such as achieving high ionic conductivity at room temperature, ensuring good interfaces between solid-state electrolytes and electrode materials, developing cost-effective solid-state-electrolytes that can compete with currently established liquid electrolyte technologies is also a hurdle for widespread adoption. Currently, very few Li-oxide conductors have been uncovered. Consequently, discovering new compositions within the Li—Al—P—O chemical space is a promising venture to uncover simple, cost-effective, high stability Li-conductors.

Information disclosed in this Background section has already been known to the inventors before achieving the disclosure of the present application or is technical information acquired in the process of achieving the disclosure. Therefore, it may contain information that does not form the prior art that is already known to the public.

The present disclosure focuses on presenting novel compositions within the Li—Al—P—O chemical space by applying a machine learning-based crystal structure prediction algorithm.

In this disclosure, novel lithium-containing oxides include the following parent compositions: LiAlPO(z ranges from −1 to 1), LiAl(PO)(z ranges from −0.5 to 0.5), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1).

The lithium-containing oxides in this disclosure can be used as a solid electrolyte material for Li batteries and/or electrode coatings for solid-state batteries.

This disclosure provides lower cost/high conductivity and high aqueous stability solid electrolyte for use in Li solid-state batteries.

A first embodiment of the present disclosure provides a lithium-containing oxide of one of the following parent compositions: LiAlPO(z ranges from −1 to 1), LiAl(PO)(z ranges from −0.5 to 0.5), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1).

A second embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is a lithium-containing oxide of the parent composition LiAlPO(z ranges from −1 to 1).

A third embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is a lithium-containing oxide of the parent composition LiAl(PO)(z ranges from −0.5 to 0.5).

A fourth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is a lithium-containing oxide of the parent composition LiAl(PO)(z ranges from −1 to 1).

A fifth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is a lithium-containing oxide of the parent composition LiAl(PO)(z ranges from −1 to 1).

A sixth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is a lithium-containing oxide of the parent composition LiAl(PO)(z ranges from −1 to 1).

A seventh embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is a lithium-containing oxide of the parent composition LiAl(PO)(z ranges from −1 to 1).

An eighth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is Li7Al4P9O32.

A ninth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is LiAl3(P3O10)2.

A tenth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is Li3Al3(PO4)4.

An eleventh embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is Li3Al2(PO4)3.

A twelfth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is Li7Al3(P2O7)4.

A thirteenth embodiment of the present disclosure provides a lithium-containing oxide of the first embodiment, wherein the lithium-containing oxide is Li3Al(PO4)2.

A fourteenth embodiment of the present disclosure provides a lithium solid-state battery comprising an anode, a cathode, and a solid electrolyte, wherein the solid electrolyte comprises a lithium-containing oxide of the first embodiment.

A fifteenth embodiment of the present disclosure provides a lithium solid-state battery of the fourteenth embodiment, wherein the solid electrolyte comprises Li7Al4P9O32, LiAl3(P3O10)2, Li3Al3(PO4)4, Li3Al2(PO4)3, Li7Al3(P2O7)4, or Li3Al(PO4)2.

A sixteenth embodiment of the present disclosure provides a lithium solid-state battery comprising an anode, a cathode, and a solid electrolyte, wherein at least one of the anode and the cathode is coated with a coating which comprises a lithium-containing oxide of the first embodiment.

A seventeenth embodiment of the present disclosure provides a lithium solid-state battery of the sixteenth embodiment, wherein the coating comprises Li7Al4P9O32, LiAl3(P3O10)2, Li3Al3(PO4)4, Li3Al2(PO4)3, Li7Al3(P2O7)4, or Li3Al(PO4)2.

The present disclosure demonstrates several novel compositions within the Li—Al—P—O chemical space with Li-ion conductivity.

In this disclosure, novel lithium-containing oxides include the following parent compositions: LiAlPO(z ranges from −1 to 1), LiAl(PO)(z ranges from −0.5 to 0.5), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1), LiAl(PO)(z ranges from −1 to 1). In this regard, it is noted that there can be lithium deficiency associated with oxygen loss in lithium oxide compounds. A general formula for this disclosure can be, e.g., LiAlPO(z ranges from −1 to 1 and w ranges from −0.5 to 0.5), LiAl(PO)(z ranges from −0.5 to 0.5 and w ranges from −0.125 to 0.125), LiAl(PO)(z ranges from −1 to 1 and w ranges from −0.125 to 0.125), LiAl(PO)(z ranges from −1 to 1 and w ranges from −0.167 to 0.167), LiAl(PO)(z ranges from −1 to 1 and w ranges from −0.125 to 0.125), LiAl(PO)(z ranges from −1 to 1 and w ranges from −0.25 to 0.25). This disclosure also includes the general formula LiAlPO(z ranges from −1 to 1 and w ranges from 0 to 0.5), LiAl(PO)(z ranges from −0.5 to 0.5 and w ranges from 0 to 0.125), LiAl(PO)(z ranges from −1 to 1 and w ranges from 0 to 0.125), LiAl(PO)(z ranges from −1 to 1 and w ranges from 0 to 0.167), LiAl(PO)(z ranges from −1 to 1 and w ranges from 0 to 0.125), LiAl(PO)(z ranges from −1 to 1 and w ranges from 0 to 0.25).

In this disclosure, novel Li-ion prototypes within the Li—Al—P—O chemical space include the following formulas: Li7Al4P9O32, LiAl3(P3O10)2, Li3Al3(PO4)4, Li3Al2(PO4)3, Li7Al3(P2O7)4, Li3Al(PO4)2.

Li7Al4P9O32 crystallizes in the tetragonal P-42c space group.

LiAl(PO)crystallizes in two distinct space groups: Aea2 and C222.

Li3Al3(PO)crystallizes in the monoclinic C2/c space group.

Li3Al2(PO4)3 crystallizes in 7 different space groups, namely, R-3, P2/c, Cc. C2/c, I432, Ia-3d, I4/a.

Li7Al3(P2O7)4 crystallizes in two different space groups: C2/c and P21/c.

Li3Al(PO4)2 crystallizes in the P-1 and C2/m phase.

High-throughput data-mining was conducted to derive novel prototype Li-containing structures, and advanced data analytics was performed to extract novel Li-ion conductors that are stable against Li metal, stable anolyte against various types of anodes such as alloy anode or graphite anode, stable catholytes and stable coating materials in all-solid state batteries.

The lithium-containing oxides in this disclosure can be made by a standard solid-state method. In this method, precursor powders are combined in a certain ratio depending on the composition of the target material. As one example, precursors may consist of lithium carbonate (LiCO), aluminum oxide (AlO), and phosphoric acid (HPO), and as another example, precursors may consist of lithium oxide (LiO), aluminum oxide, and phosphoric acid.

The precursor mixture may be mixed by a method such as ball milling or planetary milling to produce a homogeneous mixture. Mixing may be done with a suitable solvent such as ethanol, isopropanol, ethylene glycol, or acetone to assist with the uniform dispersion of the precursors.

The precursor mixture may then be heat treated to an appropriate temperature (e.g., 500-1000° C.) for an appropriate period of time (e.g., 6-12 hours) to produce a powder with the desired composition and crystal structure.

Subsequently, the powder may be compressed using a hydraulic uniaxial press to form a densely packed pellet. Heat treatment may then be applied at an appropriate temperature (e.g., 500-1000° C.) for an appropriate period of time (e.g., 6-12 hours) to produce a dense pellet which may be used as a solid electrolyte separator in a solid state lithium battery cell.

An embodiment of the aforementioned solid electrolyte separator can be assembled together with a cathode active material layer and an anode active material layer to be used in an embodiment which is a solid state lithium battery comprising a cathode active material layer, an anode active material layer, and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer, wherein the solid electrolyte layer comprises any of the aforementioned materials.

The lithium-containing oxides in this disclosure can be used as a solid electrolyte material for Li batteries and/or electrode coatings for solid-state batteries.

This disclosure provides lower cost/high conductivity and high aqueous stability solid electrolyte for use in Li solid-state batteries.

Embodiments will now be illustrated by way of the following examples, which do not limit the embodiments in any way.

A machine learning-based crystal structure prediction algorithm was applied to obtain the following compositions as set forth in Table 1.